1. Field of the Invention
The present general inventive concept relates to an image forming apparatus, an image forming system and a printing method thereof, and more particularly, to an image forming apparatus, an image forming system and a printing method thereof which reduces printing time.
2. Description of the Related Art
An image forming system includes a host device such as a computer or a personal digital assistant (PDA), and an image forming apparatus such as a printer which prints image data received from the host device on a print medium. The image forming apparatus may form a color image with developers (toner or ink), typically in four colors including yellow (Y), magenta (M), cyan (C), and black (K).
Recently, image forming apparatuses that improve the quality of color images with developers have been developed. Some colors of the developers have different gradations.
More specifically, a developer in the yellow (Y) color is classified into a dark yellow color and a relatively light yellow color to perform a color print.
In such a case, the image data which is received from the host device is continuous tone image data with 255 gradations, and thus goes through an image processing called halftoning to be converted into binary data.
A single-bit halftoning which represents only two gradations by on/off of dots has been mainly employed. Recently, however, a multi-bit halftoning which can represent more than two gradations has been developed with advanced hardware technology.
If the multi-bit halftoning is performed on the image data regardless of gradations of developers, a considerable amount of time may be required for the halftoning image processing.
Also, the multi-bit image data is larger than the single-bit image data in quantity, and print time may therefore be longer.
As for a light developer, even if an image is printed in at least three gradations, a user does not identify the gradations in the image as clearly as gradations in the image printed with a dark developer.